At the time, it felt like the beginning of the end for one of the English game's great managers. Arsenal's 8-2 loss at Manchester United on 28 August of last year was a beating so terrible that it blew apart the cracks at the club and raised searching questions about the future. Could the club's methods endure? Whisper it. Could those of Arsène Wenger?

The debate still rages, as shown at the club's AGM last Thursday, even if the board of directors, rather than Wenger, tends to bear the brunt of the frustration. But as he prepared to revisit the scene of the nightmare, for Saturday's early Premier League kick-off at Old Trafford, it was a cool and composed Wenger who sought the bigger picture. "They say a pessimist is a well-informed optimist," he said, with a smile. "On the day, I was badly informed."

There were no wise-cracks on the eve of last season's trip to United. Wenger knew that Arsenal were vulnerable, having given everything in stifling heat four days earlier to squeak past Udinese in the Champions League play-off. Injuries had depleted them further, particularly in defence, while the ructions from the sales of Cesc Fábregas and Samir Nasri were loud and disorienting.

As the United goals flew in that day, even the hardest home supporter might have felt for Wenger. Sir Alex Ferguson expressed his sympathy and the emotional aspect of the defeat, Wenger's heaviest in English football, has retained its capacity to haunt. Wenger recalled the humiliation and embarrassment as he looked ahead to Saturday's game.

Yet there is another part of him that has learned to cast aside extreme feelings after a freak result, even in victory, such as his team's 7-5 League Cup win at Reading on Tuesday, although he noted it was "easier to cope with the irrationality than when you lose". Wenger coped in the aftermath of Old Trafford by repeatedly reminding himself and his players of the day's special circumstances. He has not brought up the 8-2 with his squad in this week's preparations.

"There is an emotional aspect in a defeat like that, but the football aspect, as a manager, has no real meaning," Wenger said. "There is no mathematical consequence. We lost a game, that is all. It was easy to explain. We gave everything in Udinese in 35C heat at night and I knew that we would be dead. We lost vital defensive players in that game and we went out very exposed.

"Honestly, the result did not affect us. You feel humiliated but after that, the next game, when you win, you don't focus on that. When you lose a big game like that in the way we did, it is to get over the hurdle in the next three weeks."

Wenger's immediate response was to hit the market like a Christmas Eve shopper. In came a mixed bag of new signings – Wenger has been most happy with Mikel Arteta and Per Mertesacker – and, in light of injuries and the business of this past summer, he is likely to start with only one of last season's Old Trafford lineup. Wenger's selection teaser is whether to play Theo Walcott, the hat-trick hero against Reading, or Aaron Ramsey; both started in the 8-2. Otherwise, the players are untouched as individuals by the trauma.

It was interesting to hear Wenger admit to one particular mistake in the drubbing. He said that the scoreline was 4-1 with 20 minutes to go, which was not quite right; Wayne Rooney put United 4-1 up in the 64thminute and it was 6-1 after 70 minutes. But Wenger's point was that the result reached record levels in the closing stages and it was partly due to his desire to retain an attacking outlook, even after Carl Jenkinson was sent off in the 77th minute.

"I decided to go for an offensive … to try to come back with 10 men and we were already dead," Wenger said. "After that, we paid for it so, maybe, I should have said, 'Let's keep it tight and go out with 4-1.' But we wanted absolutely to give ourselves a chance to come back. Maybe we shouldn't have done that."

United said similar things after their 6-1 derby disaster against City last season, when they conceded three times after the 89th minute, but it is in the make-up of both teams to go for it. Wenger mused that he had been the victim of his nature but his philosophy cannot change.

"You cannot play with [Jack] Wilshere, [Santi] Cazorla and Arteta and say, 'Look, we only defend.' Sometimes, when you don't win, you first maybe have to learn not to lose before you can win again so you give a bit more security to the team. I have done that as well. But our basic philosophy is to go forward and attack."

Ferguson, for his part, is convinced Saturday's match will be a tighter affair than last season's 8-2. "It won't happen again, that's for sure," he said. "No point living in the past anyway, just got to look forward. It could be a way of motivating Arsenal, that's possible, but I think we have to have the motivation to make sure we win the match."

Wenger, as ever, will arrive at Old Trafford full of hope, mindful that victory would ignite Arsenal's Premier League campaign. He has noted defensive weaknesses about United, which were exposed by Tottenham Hotspur in September, although he admitted his team had hardly looked rock solid at Reading. It promises to be another wild ride.